Investigation of implicit avoidance of displacement-related stimuli in offspring of trauma exposed, forcibly-displaced individuals

Long-term affective and non-affective brain alterations across three generations following the genocide in Cambodia

The literature has largely indicated that trauma can lead to post-traumatic stress disorder (PTSD) and alterations in brain functioning. However, to what extent these alterations remain present decades after the traumatic event, and how the next generations may also suffer from them, remains unclear, especially in a non-Western culture. Uniquely, the present project focused on survivors of the Cambodian genocide and the subsequent two generations to determine whether brain alterations are observable approximately five decades after the traumatic event and in subsequent generations from the same society. Using portable electroencephalography (EEG), we used four experimental tasks-two targeting non-affective processing (i.e., sensory gating, oddball) and two targeting affective processing (i.e., emotion recognition, threat processing). Results indicated that although the rate of PTSD symptoms was similar across generations, the affective reaction to threat for the LPP and FMθ was primarily observed or intensified in the directly affected generation (i.e., G0), regardless of the presence of PTSD. We also observed that G0 exhibited reduced attenuation over standard tones in the oddball task for the N100 and a reduced sensory gating effect on the auditory P200. The present study underscores that affective and non-affective alterations might still be present decades after a trauma, but are not necessarily observable in subsequent generations. Our results also support a dissociation between reported PTSD symptoms and neural alterations.

How interindividual differences shape approach-avoidance behavior: Relating self-report and diagnostic measures of interindividual differences to behavioral measurements of approach and avoidance

Responding to stimuli in ambiguous environments is partially governed by approach-avoidance tendencies. Imbalances in these approach-avoidance behaviors are implicated in many mental disorders including anxiety disorders, phobias and substance use disorders. While factors biasing human behavior in approach-avoidance conflicts have been researched in numerous experiments, a much-needed comprehensive overview integrating those findings is missing. Here, we systematically searched the existing literature on individual differences in task-based approach-avoidance behavior and aggregated the current evidence for the effect of self-reported approach/avoidance traits, anxiety and anxiety disorders, specific phobias, depression, aggression, anger and psychopathy, substance use and related disorders, eating disorders and habits, trauma, acute stress and, finally, hormone levels (mainly testosterone, oxytocin). We highlight consistent findings, underrepresented research areas and unexpected results, and detail the amount of controversy between studies. We discuss potential reasons for ambiguous results in some research areas, offer practical advice for future studies and highlight potential variables such as task-related researcher decisions that may influence how interindividual differences and disorders drive automatic approach-avoidance biases in behavioral experiments.